MODAL
INSTALLATION, USE AND
SERVICING INSTRUCTION
(to be kept by the user)
26740 - 11/04
rev. 0
2
GENERAL INFORMATIONS
Introduction
This manual supplies a summary of what has to be followed during the installation, use and servicing of the UNICAL boilers, MODAL range.
Choice of the boiler
For a correct choice and application of the MODAL boilers it is necessary to follow the instructions given in this manual.
Installation
The installation of the boilers and the auxiliary equipments, related to the heating system, must be in conformity with all the regulations and
rules in force.
It is law that all the gas appliances are installed, commissioned and serviced by a registered installer in accordance with the regulations below.
Failure to install appliances correctly coul lead prosecution. It is in your own interest, and that of the safety, to ensure the law is complied with.
The following must be complied with:
Current Building Regulations and Clean Air Act.
Water authority regulations.
Local Authority Regulations and Regional Bylaws.
Gas Safety Regulations.
Any special regional requirements of local Electricity and Gas undertaking.
Fire Service and Insurance Company requirements.
Commissioning
The main purpose of the commissioning is to verify the correct operation of all the safety and control devices.
Before leaving the installation the commissioner has to control the operation of the boiler for, at least, a complete working cycle.
Guarantee
The boiler guarantee is bound to the compliance of the the requirements stated in this manual, and any non-fulfilment or modification will make
it void.
Normative
It is the responsibility of the installer to fulfil all the regulations concerning the boiler house, the safety devices, the chimney, the fuel supply
lines, the electrical installations and all the other local requirements and safety instructions.
Approvals
The UNICAL boilers, MODAL range, have been tested and CE certified for the gas operation by GASTEC ITALIA, who has recognised to these
boilers the conformity certificate according to the following directives:
- Gas Appliances Directive (90/396 CE), compulsory as per 1st January 1996;
- Efficiency Directive (92/42 CE), compulsory as per 1st January 1998;
- The conformity to the Low Voltage Directive (73/23 CE), compulsory as per 1st January 1997 has been verified and ascertained by GASTEC
ITALIA.
The conformity to the EMC (Electro Magnetic Compatibility 89/336 CE), compulsory as per 1st January 1996, is not applicable to the MODAL
boilers because they do not have electronic components.
For the time beeing there are no European Directives covering the oil fired boilers, except the Efficiency Directive (92/42 CE).
Data plate and Serial No.
The data plate, supplied in a separate enveloppe with the relevant documents, makes reference to a serial No, embossed in an aluminium plate
riveted to the front tube plate in the lower RH side corner.
Use of the boiler
This boiler has to be used for heating the water at a temperature not higher than the boiling temperature in the installation conditions.
WARNING
When the boiler is operated with a pressure jet gas burner, because it does not belong to any of the categories among those listed in the Annex II to
the Directive 97/23/CE (regarding pressure equipment) and beeing, furthermore, mentioned in the Directive 90/396/CE (Gas Appliance Direc-
tive) to which the art. 1, clause 3, paragraph 6.5 makes reference, it is excluded from the scope of the Directive.
3
GAS SAFETY (INSTALLATION
AND USE) REGULATIONS,
1994
It is law that all gas appliances are installed
and serviced by a CORGI registered installer
in accordance with the above regulations.
Failure to install appliances correctly could
lead to prosecution.
It is in your own interest, and that of safety,
to ensure the law is complied with.
The installation of the boiler MUST also be
in accordance with the latest I.E.E. Wiring
Regulations, local building regulations, bye-
laws of the local water authority, the building
regulations and the Building Standards
(Scotland) and any relevant requirements of
the local authority.
Detailed recommendations are contained in
the following
British Standard Codes of Practice:
BS 6891 Low pressure installation pipes.
BS 5449 Forced circulation hot water
systems.
BS 5546 Installation of gas hot water
supplies for domestic purposes
(2nd Family Gases).
BS 6644 Ventilation (for gas appliances of
rated input exceeding 60 kW).
HEALTH & SAFETY
DOCUMENT No. 635
The Electricity at Work Regulations, 1989.
The manufacturer's notes must NOT be
taken, in any way, as overriding statutory
obligations.
IMPORTANT. These appliances are CE
certificated for safety and performance. It is,
therefore, important that no external control
devices, e.g. flue dampers, economisers etc.,
are directly connected to these appliances
unless covered by these Installation and
Servicing Instructions or as other-wise
recommended by Unical in writing.
If in doubt please inquire.
Any direct connection of a control device not
approved by Unical could invalidate the
certification and the normal appliance
warranty.
Notes.
To obtain the gas consumption:-
a. For l/s divide the gross heat input (kW) by
C.V. of the gas (MJ/m³).
b. For ft³/h divide the gross heat input (Btu/h)
by C.V. of the gas (Btu/ft³).
4
COSTRUCTIONAL-DIMENSIONAL
TECHNICAL CHARACTERISTICS .................... page 5
1.1 Construction of the MODAL boilers ...................................... page 5
1.2 Dimensions and hydraulic connections of MODAL boilers . page 6
INSTALLATION .................................................................. page 7
2.1 Packaging .............................................................................. page 7
2.2 Handling ................................................................................. page 7
2.3 Positioning in the boiler house .............................................. page 7
2.4 Casing assembly ................................................................... page 8
2.5 Connection to the chimney ................................................... page 9
2.6 Feeding water quality ............................................................ page 9
2.6.1 Shunt pump .................................................................. page 9
2.6.2 Choice of the burner .................................................... page 9
STANDARD PANEL BOARD .................................. page 10
3.1 Panel board type 21057 - functions description .................. page 10
3.2 Electrical wiring diagram for single phase burner & pump .. page 10
COMMISSIONING AND OPERATION ............ page 11
4.1 Positioning the turbulators .................................................... page 11
4.2 Preliminary check .................................................................. page 11
4.3 First commissioning .............................................................. page 11
4.4 Operation of the boiler ........................................................... page 12
4.5 Switch off of the boiler ........................................................... page 12
MAINTENANCE ................................................................ page 13
5.1 General rules ......................................................................... page 13
5.2 Ordinary maintenance ........................................................... page 13
5.3 Extraordinary maintenance ................................................... page 13
5.4 Cleaning of the boiler ............................................................ page 14
5.5 Check of the boiler operation ................................................ page 14
5.6 Check of the burner operation .............................................. page 14
5.7 Boiler house ........................................................................... page 14
1
2
3
4
5
5
1
CONSTRUCTIONAL-DIMENSIONAL
TECHNICAL CHARACTERISTICS
reason, from L.H. or R.H. side.
The outer shell is insulated with a glass wool
matress, thick 60 mm, protected by a textile
in mineral fiber.
The upper part of the outer shell is equipped
with uplift hook(s).
The boilers are provided with two 1/2" bulb
holders with inner diameter of 15 mm (for 3
bulbs each), suitable to locate the thermostats
and thermometer bulbs.
The casing side panels are provided with
holes for the cables of the electrical supply,
of the pumps, of the burner and any other
1.1 - CONSTRUCTION OF
THE MODAL BOILERS
The construction completely satisfies the
requirements of the EN 303- part 1.
The sheet metal parts of the pressure vessel
are manufactured of certified carbon steel,
type S235JRG2, according to EN 10025, with
melting certificate 3.1.B, according EN
10024; whereas the pipes are of steel ST 37.0
according to DIN 1626.
The welders and the WPS (Welding Procedures
Specifications) have been approved according
to EN 287 and EN 288 by TUEV (DE).
The boilers are equipped with a reversible
inged door, which can be opened, for this
fig. 1
auxiliary equipment.
Note:The MODAL boilers are to be equipped
with ON/OFF burner; alternatively they an be
equipped with a two stage or modulating
burner, provided the minimum reachable heat
input is not lower than the figure shown on
the data plate for the fuel used on site.
6
Fiber wool
Ceramic fiber
Blind burner plate 250x250
Burner plate insulation gasket 250x250
ø 180
ø 150
75
ø 180
MD 105÷186
MD 233÷291
Fiber wool
Ceramic fiber
Blind burner plate 200x200
Burner plate insulation gasket 200x200
ø 130
ø 130
75
1.2 - DIMENSIONS AND HYDRAULIC CONNECTIONS OF MODAL BOILERS
4 Sight glass
T1 C.H. flow
T2 C.H. return
T3 Flue connection
T4 Burner axis
T5 Boiler drain
1 Panel board
2 Burner connecting plate
3 Cleaning door
64
76
93
105
116
140
163
186
233
291
(64)
55.000
(76)
65.000
(93)
80.000
(105)
90.000
(116)
100.000
(140)
120.000
(163)
140.000
(186)
160.000
(233)
200.000
(291)
250.000
690
690
690
760
760
760
760
760
860
860
722
722
722
812
812
812
812
812
937
937
990
990
990
1205
1205
1205
1385
1385
1437
1687
190
190
190
190
190
190
190
190
190
190
305
305
305
350
350
350
350
350
421
421
480
480
480
500
500
500
500
500
580
580
115
115
115
130
130
130
130
130
165
165
--
--
--
--
--
--
--
--
1482
1732
200
200
200
200
200
200
200
200
250
250
130
130
130
180
180
180
180
180
180
180
Rp ¾
Rp ¾
Rp ¾
Rp ¾
Rp ¾
Rp ¾
Rp ¾
Rp ¾
Rp ¾
Rp ¾
86
86
86
126
126
126
151
151
203
247
0,10
0,13
0,16
0,10
0,10
0,14
0,20
0,25
0,22
0,30
1,5
1,8
2,5
3
3
5
8
14
18
22
5
5
5
5
5
5
5
5
5
5
MODAL
Type
Output
(kW)
kcal/h
Input
(kW)
kcal/h
Weight
kg
Max.
allow.
working
pressure
bar
Smoke
side
press.
losses
mm w.c.
Water side
press.
loss(*)
m w.c.
Boiler
capacity
liters
T5
ISO 7/1
T4
Ø
mm
T3
Ø
mm
H
mm
G
mm
F
mm
E
mm
D
mm
C
mm
B
mm
A
mm
DIMENSIONS
Rp 1½
Rp 1½
Rp 1½
Rp 2
Rp 2
Rp 2
Rp 2
Rp 2
DN 65
DN 65
(71)
61.000
(84)
72.000
(102)
88.000
(115)
99.000
(128)
110.000
(155)
133.000
(180)
155.000
(206)
177.000
(258)
222.000
(322)
277.000
(*) Pressure losses with a water flow rate related to a delta T of 15 K.
330 x 670
330 x670
330 x 670
390 x 850
390 x 850
390 x 850
390 x 1030
390 x 1030
470 x 1070
470 x 1320
Combustion
chamber
dimensions
Øi x Lg
mm
fig. 2
* - In the models MODAL 233 and MODAL 291 the connections T1-T2 are flanged.
The dimension H is applicable only to the models MODAL 233 and MODAL 291
212
212
212
309
309
309
349
349
485
555
T1 - T2
ISO 7/1
UNI 2278 PN16
CONNECTIONS
DETAIL FOR DOOR
DRILLING
MODAL 64÷93
DETAIL FOR DOOR
DRILLING
MODAL 105÷291fig. 3 fig. 4
E
B
D
A
4
2
1
T3
F
G
T2-T5
121
258
T1e
T4
C
H
3
7
2.2 - HANDLING
2.1 - PACKAGING
The MODAL boilers are supplied complete
with door and smoke chamber already fitted,
whilst the casing with the insulation matress are
contained in separate cardboard packaging(s).
The panel board and the accessories are inside
the combustion chamber.
Before starting the installation make sure that
2
INSTALLATION
The boiler can be moved into position by
lifting, through the upper hook(s), or by the
use of rollers placed under the strong L
profiles of the basement.
2.3 - POSITIONING IN THE
BOILER HOUSE
The installation of the boiler must be in
accordance with the relevant requirements
of the Gas Safety Regulations, current I.E.E.
Regulations, local water authority bye-laws
and it should also comply with any relevant
requirements of the local gas supplier, local
authority and the relevant Standard Codes
of Practice and building regulations.
The boiler house must be ventilated through
permanent openings having a total surface
not lower than 1/30
th
of the floor area of the
boiler house, with a minimum of 0.5 m
2
.
Ventilation by grilles communicating directly
with the outside air is required at both, high
and low levels.
The boiler must be positioned so that there
is enough space available for the following:
- Access around the boiler fore servicing
- Space to open the boiler front door
- Space to access the burner.
The installation of the boiler as close as
possible to the chimney position is highly
recommended.
To allow the cleaning of the smoke pipes, in
front of the boiler a clearance equal to the
length of the boiler, has to be available.
With the boiler door opened at 90°, the distance
between the front of the door and the adjacent
wall must be equal, at least, at the length of
the burner.
The boiler must stand on a non-combustible
floor (i.e. concrete or brick), which must be
flat, level and of a suitable load bearing
capacity to support the weight of the boiler
(when filled with water) and any ancillary
equipment.
Once the installation has been made the
boiler must result perfectly horizontal and well
stable (to avoid vibrations and noise).
fig. 5
x = not shorter than the boiler body
the length and the width of the boiler body
received correspond to the dimensions of the
ordered boiler, shown in the previous tables
and that the cartons, containing the casing,
or part of it, are marked with the same model.
In addition to the a. m. panel board, packed
in its own carton, in the combustion chamber,
as accessories, there are also:
- a carton containing the flanges for flow,
return and safety connections (if applicable)
with relevant gaskets and bolts, the
cylindrical brush for the cleaning of the
smoke pipes.
- cleaning brush handle extension.
- turbulators extractor.
- ceramic fiber rope for the insulation
between the door and burner blast tube.
If it necessary, due to the dimensions of the
boiler, it is possible to remove the front door
and the smoke chamber to facilitate the
introduction in the boiler house.
X
8
7
6
3
5
4
1
2
5
1
3
2
4
6
6
2.4 - CASING ASSEMBLY
N.B. It is suggested to verify that the boiler is
positioned in its final place and that all the
hydraulic connections are made correctly
before starting the casing assembly.
Before opening the casing carton(s) make
sure they are stamped with the right boiler
model, corresponding to the boiler to be
installed.
N.B.: The packaging containing the panel
board is delivered inside the combustion
chamber, as well as the documents
and the guarantee certificate.
Refer to diagram fig. 6 & 7 for details
A. Fit the insulation blanket (1) onto the boiler
shell and secure it in to place using the
elasticated straps (2) provided, ensuring
that the metal clips grip in to the external
surface of the insulation.
B. Locate the side panels (3) and (4) with the
lower bend inside the bottom L profiles and
the upper bend in the seats of front and
rear tube plates.
To determine which is the left and right
panel ensure that the cable glands are po-
sitioned facing toward the front edge.
C) After removal of the two side screws from
the panel board rotate its cover frontwards.
Fit the panel board to the upper panel (5)
and after having passed the cables
(mains, room thermostat, burner etc.)
through the cable glands fitted to the side
panel insert these cables and the capillaries
of thermometer and thermostats through the
slots on its base. Fit the casing upper
panel, complete with the panel board, to
the side panels (3 & 4), directing the
capillaries of thermostats and thermometer
to the bulb holder.
D) Insert the thermometer and thermostat
bulbs in the bulb holders as shown in fig. 7
and connect the mains, the burner, the
pump(s) and any ancillary equipment to
the panel board.
Close the panel board.
E) Fit the upper panel rear reinforcement (6).
F) Remove the protective paper film from
data plate and ventilation requirement label
(7) and fit them at the top front corner of
the most accessible side panel after
removal of dust from the surface.
The data plate and label are in the
documents envelope.
fig. 7
1 Thermometer bulb
2 Working thermostat bulb
3 Safety thermostat bulb
4 Minimum thermostat bulb
5 Bulb holders
6 Bulb retaining clip
fig. 6
9
L
Ø A
2.5 - CONNECTION TO THE
CHIMNEY
The chimney has a foundamental importance
for the good operation of the boiler.
Due to the low temperature of the smokes
during the intermittent operation, it is necessary
that the chimney is perfectly impermeable to
the condensate of the combustion products
and manufactured with corrosion resistant
materials.
The different connections must be sealed with
an approved boiler putty so that the inlet of
fresh air, with consequent increase of the
possibility of condensate formation, is avoided.
Furthermore the possible condensate or rain
water comming from the chimney must be
avoided from entering the smoke chamber
of the boiler.
2.6.2 - CHOICE OF THE BURNER
The correct choise and the adjustment of the
burner are foundamental for the best operation
of the boilerand then they shall be accurate
and not under evaluated.
The burner will be selected by verifying that
its working diagram (fuel flow rate - pressure
in the furnace) is compatible with the same
features declared for the boiler.
Remember that the smoke side resistance,
i.e. the counterpressure in the furnace, are
referred to "0" draught at the chimney base.
It is also convenient that the burner blast tube
have its length not shorter than that shown
in table 8 and that the flame have a shape
suitable to the characteristics of the MODAL
furnace.
In fact to better exploit all the heating surface
of the reversed flame furnace it is necessary
to use burners capable to guarantee a long
and narrow flame at all operating conditions
or also at minimum input in case of two stage
or modulating burners.
BOILER TYPE
MODAL 64 ÷ 93
MODAL 105 ÷ 140
MODAL 163 ÷ 186
MODAL 233 ÷ 291
øA
mm
L
mm
130
180
180
180
150
170
170
170
BURNER BLAST TUBE DIMENSIONS
fig. 8
2.6 - FEEDING WATER
QUALITY
- The chemical-physical characteristics of
the C.H. system and reinstatement water
are foundamental for the good operation
and safety of the boiler.
- Among the inconvenients caused by the
bad quality of the feeding water the most
frequent and serious is the scaling of the
heat exchange surfaces.
- Less frequent, but also dangerous, is the
corrosion of the water side surfaces of all
the circuit.
- It is well known that the lime, due to its
very low thermal conductivity, reduces the
heat transfer so that also a scaling of a
few millimeters produces very dangerous
localized overheating.
1 mm of lime reduces the heat transfer
from metal to water by 10%.
It is suggested to make a water treatement
in the following cases:
A- high hardness of the water available on
site (higher than 20°f).
B- very large C.H. systems.
C- large quantities of reinstatement water
due to water leaks.
D- subsequent fillings of the system due to
maintenance works.
E- mixing of different metals in the CH circuit.
For the treatment of filling water it is suggested
to address them self to specialized firms.
The same firms are able to provide for the
descaling of the boilers.
Every C.H. system needs reinstatements of
water, du to evaporation, small or large water
leaks or for maintenance works.
It is, therefor, necessary to be able to evaluate
the entity of the reinstatement water to avoid
inconvenients due to untreated water.
For that reason it is suggested to fit, in the
feeding line to the boiler, a water meter for
small capacities.
Too short flames can cause a localized
overheating of the front part of the furnace,
and the combustion products, not sufficiently
cooled down, entering the smoke pipes at a
too high temperature, can cause important
damages to the boiler.
The burner manufacturing companies are
able to supply the flame dimensions
developped by their burners.
More informations are given in the paragraph
"Commissioning". .
As far as the cross section and the high of
the chimney is concerned, it is necessary to
make reference to the local and national rules
in force.
In the flue pipe, between the boiler and
the chimney, convenient sampling points
for smoke temperature and combustion
products analysis must be provided.
2.6.1 - SHUNT PUMP
The MODAL boilers must always operate in
forced circulation hot water systems and with
a minimum return temperature of 55 °C..
So, it is suggestable to adopt a shunt pump,
having also an anti-condensation purpose,
installed between the flow and return
connections, upstream an eventual 3 or 4 way
mixing valve.
This pump will be sized according to the
following formula:
Q = P x 22
where Q = Water flow rate in liter/h
P = Boiler nominal output in kW
and the manometric head 1-2 m w.c.
10
3.1 - PANEL BOARD
TYPE 21057 - FUNCTIONS
DESCRIPTION
Through the main switch 11 the panel board
and all the equipments connected to it will
be under power.
The switches 12 & 13 switch On and OFF
the power to the burner and the Heating pump
(via a relay, if necessary).
With the thermostat 32 the working
temperature of the boiler can be adjusted.
This thermostat is provided with a DPDT
contact, for the control of a two stage burner.
The differential between the switching points
of the two double pole is 6°C (not adjustable).
The minimum thermostat, accessible through
the opening of the panel board cover, switches
OFF the C.H. pump during the reacing of the
steady state and up to the obtention of 50 °C
within the boiler.
On the electrical supply line to the boiler a
switch with fuses is to be forseen.
3
STANDARD PANEL BOARD
fig. 9
3.2 - ELECTRICAL WIRING DIAGRAM FOR SINGLE PHASE BURNER AND PUMP
Te11
st
stage working thermostat (60°C÷90°C)
Te22
nd
stage working thermostat (54°C÷84°C)
Tm Minimum thermostat (50°C)
Ts High limit thermostat (100°C)
Pi C.H. pump
A Burner lockout warning lamp (eventual)
Ph Phase (230V ~50Hz)
N Neutral
F1 General fuse (max 4A)
Ib Burner switch
IG Illuminated main switch
Ipi C.H. pump switch
fig. 10
11 Illuminated main switch
12 Burner switch
13 C.H. pump switch
31 High limit thermostat
32 Working thermostat
41 General fuse
42 Thermometer
B Hourmeter for 1
st
stage operation
C Hourmeter for 2
nd
stage operation
In case the room thermostat is fitted,
remove the link between 11 and 12
31
42
11
41
12
13
32
E
E
E
E
L1 T2N S3T1 B4
IG
11
41
32
32
12
13
31
230V~ 50Hz
2
1
3
4
4-4
24
14
C
2
1
22
12
21
11
C
2
G-V
6-6
7-7
8-8
9-9
10-10
Ts
7
14 15
16
6 95 8 10
B
A
20
21
24
Pi
18
17
23
22
19
11
12
Ipi
Ib
(50°C)
(60°÷90°C)
(54°÷84°C)
(100°C)
Tm
Te1
F1 (max 4 A)
Te2
13
C
N
Ph
B5
T6
T7 T8
1 stage burner plug
st
2 stage burner plug (optional)
nd
11
COMMISSIONING AND OPERATION
4
4.1 - POSITIONING THE
TURBULATORS
The MODAL boilers are foreseen to operate
at the nominal output declared. If the boiler
is used at a lower ourput, the resulting smoke
temperature can be lower than 160°C and in
this case the turbulators can be positioned
against the rear wall of the smoke chamber.
In the other cases the turbulators are
positioned inside of the relevant pipes at
Detail 1:
Fit the brush handle extension
onto the turbulator remover
Withdraw the pin from turbulator.
Detail 2:
Fit the pin in the radial hole with a hammer.
Detail 3:
Screw the turbulator remover onto the
turbulator.
Detail 4:
Turn up to unblock the turbulator.
Detail 5:
Withdraw the turbulator
Detail 6:
Turn the remover counterclockwise to
release the turbulator
The procedure from detail 3 to 6 has to be repeated for all the turbulators.
Turbulators removal
fig. 11
4.2 - PRELIMINARY CHECK
Once all the hydraulic, electrical and fuel
connections have been made, before starting
the boiler we suggest to ascertain that:
- The expansion vessel and the pressure
relief valve are correctly connected and
are in no way interceptable.
- The bulb of thermometer, working, high
limit and minimum thermostats are well
secured into their proper bulb holder.
- The turbulators are correctly fitted in all
the smoke pipes.
- The C.H. circuit has been washed and
rinsed and is free from solid impurities.
- The C.H. circuit is filled with water and has
been completely purged.
- The pumps operate properly.
- The flow switch, the pressure relief valve,
and the overheating discharge valve, if
any, are adjusted at the right value.
- The fuel, hydraulic, electrical and safety
connections are executed in conformity
with national and local requirements in
force.
- There are no water leaks.
- The burner has been fitted according to
the instructions of the burner
manufacturer.
- The mains voltage and frequency are
compatible with the burner and the
electrical equipment of the boiler.
- The burner is adjusted for the fuel type,
among those listed in the burner data plate,
available on the installation site, and the
burner output range is compatible with the
boiler output.
- In the boiler house there are also the burner
instructions.
- The C.H. pipes are properly insulated.
- The C.H. system is capable to absorb the
heating quantity produced at the first start
of the burner, during the test period.
The shunt pump is installed as prescribed
in the paragraph 2.6.1.
approx 2 to 4 cm from the front tube plate.
The commissioning of the burner will be done
under the responsibility of a qualified burner
technician, sent by the burner manufacturer.
In that occasion a commissioning report will
be filled in.
4.3 - FIRST COMMISSIONING
At the commissioning stage of the boiler a
qualified technician has to perform the following
checks:
- Internal and external sound test of burner
and fuel feeding pipe;
- Adjustment of the fuel throughput according
to the nominal input of the boiler (it is
convenient to remember that the nominal
input can be obtained by sharing the output
shown in the table of pages 6), between
the 1st and the 2nd stage, knowing that
the 1st stage flame can go down to the
60% of the nominal output.
Proceed, then, in the following way:
- Open the fuel feeding cock and check that
there are no leaks in the feeding line,
- Ascertain that all the switches of the
panel board are in OFF position and adjust
12
4.4 - OPERATION OF THE
BOILER
The HIGH EFFICIENCY MODAL boilers are
forseen to operate with a return water
temperature never below 54 °C when operated
on light oil, and never below 59 °C when
operated on gas, to avoid (or, at least, to
reduce) the smoke acid condensation
phenomenon, which can be the reason of a
premature deterioration of the steel boiler
body. The working thermostat, pos. 32 of the
panel board, must be set at a temperature of
approximately 80 to 85 °C.
The room temperature will be compulsorily
adjusted trhough a mixing valve and,
eventually, an outer compensator.
To homogenise the water temperature, or
avoid as maximum as possible, returns into
the boiler at a temperature below 54 °C when
operated on oil, or 59°C when operated on
gas, a properly dimensioned shunt pump
must be fitted between flow and return pipes
of the boiler.
N.B.The metal sheet corrosion due to the acid
condensate is not covered by the guarantee
because it depends only from the operation
of the C.H. system.
The MODAL panel board is equipped with a
low temperature thermostat not allowing the
operation of the pump when the boiler
temperature is below 50 °C (protection against
cold starts).
4.5 - SWITCH OFF OF THE
BOILER
- Switch OFF the burner (switch No.12 to 0
position).
- Leave the pumps working up to when they
are not stopped by the minimum thermostat.
- Switch Off the power to the boiler panel
board.
- If it is decided not to use the boiler for a
long period close also the gate valves of
the fuel.
the working thermostat to the minimum
position.
- Switch ON the panel board through the
main switch.
- Switch ON the C.H. pump: it will start to
rotate as soon as the minimum water
temperature thermostat detects 50°C.
- Switch the burner ON.
- Position the working thermostats of 1st
and 2nd stages to the maximum setting
to create a heat request.
During this phase check that:
- There are no smoke leaks from the front
door, the burner plate and the chimney
connection.
- There is a draught at the chimney base
between 2 and 4 mm w.g.
- There are no water leaks.
- The different thermostats and the other
installation safety devices work properly.
- The shunt pump operates correctly.
- The burner ignition is good.
- The burner characteristics (main
adjustments and nozzle type) correspond
to the boiler data plate.
With a burner properly adjusted it must be
possible to reach easily, from a smoke sample
taken at the chimney base, the values given
below:
1) With light oil having a maximum viscosity
of 1.5 °E at 20 °C:
- CO2 = 12 to 13 %
- Smoke index < 1
- Smoke tempearture = 190 to 210 °C
2) With Natural Gas:
- CO2 = 9 to 10 %
- Smoke temperature = 180 to 200 °C
(values related to a clean boiler, with water
at 70 °C).
It is suggested to adjust the fuel throughput
to the actual needs of the C.H. installation
(avoid to overcharge the boiler), without
exceeding the a.m. smoke temperatures
(never go below 160 °C).
13
MAINTENANCE
5
5.1 - GENERAL RULES
- All the operations must be performed by
qualified personnel .
- Affix a Warning poster, to the entrance of
the boiler house, signalling: WARNING
...........boiler under maintenance.
- The operations must be performed after
having switched Off power supply
(eventually removing the fuses to avoid
accidental startings of the burner) and
5.2 - ORDINARY
MAINTENANCE
The operation conditions of the boiler are
notably varying from case to case and depend
on the fuel used,on the burner adjustment, on
the number of startings, on the characteristics
of the heating system, etc., for which it is not
possible to establish previously an interval
of time between a service and the following
one.
It is therefore necessary that the technician
establishes the interval in base to a first
observation of the smudging state of the
smoke circuit.
Generally speaking we recommend the
followings intervals of cleaning according to
the type of fuel:
- Gas fired boilers: once a year.
- Oil fired boilers: twice a year, or more often
if there is reason to doubt of their good
operation.
In any case local rules in terms of maintenance
have to be followed.
We advise, however, to shake the turbulators
- without removing them from the smoke pipes
- at least once every 15-20 days of boiler
operation to avoid that the combustion
residues can stop them so much to make
5.3 - EXTRAORDINARY
MAINTENANCE
Extraordinary maintenance of end season
or for long periods of inactivity.
It will be necessary to perform all the operations
described in the preceding chapter and
besides:
- Check the state of consumption of the
turbulators to replace them in time.
- To facilitate the extraction of the turbulators,
with the MODAL boilers a special
extractor is supplied.
- After the cleaning of the smoke circuit it
is convenient to pass in the pipes smoke
and in the furnace with a rag soaked of
diluted solution of caustic soda.
After having let to dry cross again all the
surfaces with a rag soaked of oil.
Perfectly close the the burner air intake
to avoid a continuous passage of damp
air through the boiler recalled by the chi-
mney it self.
It is advisable to put inside the furnace
after having closed the valves of feeding
of the fuel (particularly if gas is involved).
- To protect from the dust the electric
equipments of the boiler house, the boiler
panel board and the burner.
- Protect themselves with convenient suits,
gloves, glasses and masks, use a vacuum
cleaner for the removal of the soots and
and put them in the special containers with
the indication of the content.
- The possible closing of valves of the
heating circuit must be indicated by a
warning signal.
To get a good operation and the maximum
boiler efficiency, a regular cleaning of the
combustion, the smoke pipes and the smoke
chamber is necessary.
some alive mortar that has an hygroscopic
action.
- Do not empty the C.H. system and the
boiler.
- Protect the screws with graphitized fat,
nuts and pivots of the door.
- Show all the operations that must be
perform to the following put into operation,
particularly the operation of the shunt
pump must be checked.
their removal extremely difficult.
During the operations of ordinary maintenance
it will be necessary to brush the tube bundle
- after the removal of the turbulators - and
the furnace and collect the soots through the
cleaning doors on the smoke chamber.
Besides it will be necessary to verify the
good operation of the protection and control
devices (thermostats, thermometers) of the
boiler and of the plant (manometers, flow
and pressure switches, expansion vessels)
and all the safety devices.
In this occasion it will be necessary to notice
the quantity of reinstatement water used and
decide, also in base to its hardness, an
intervention of preventive descaling.
It must be considered that the calcium and
magnesium salts dissolved in the raw water,
with repeated reinstatements, can cause
deposits in the boiler that hinder the inner
circulation and subsequent overheating of
the wall plates with possible serious damages
that cannot be attributed to the constructive
geometry and/or to the materials used and/
to the constructive technique and, therefore,
they are not covered by guarantee.
On the occasion of the ordinary maintenance
it is useful to perform a small discharge
from the boiler to verify if sludges escape.
In affirmative case, it will be necessary to
prolong the discharge up to get clear water.
At the end of the drainage it will be necessary
to reestablish the level of the water in the
system.
At the end of the smoke circuit cleaning, to
the next restart check around the burner
plate and the smoke chamber for smoke
leaks. In the case some smoke leaks were
noticed, first of all tighten the screws fitting
the smoke and, not getting result, it will be
necessary to replace the sealing gasket.
Similarly it will be necessary to act on the
front door, increasing at first the tightening
of the screws and then, if necessary, by
replacing the whole gasket.
At the end check and, if necessary, restore
the sealing of the connection of the chimney
and of the burner with the door.
The performed operations must be recorded
on the log book of C.H. system.
14
5.4 - CLEANING OF THE
BOILER
Follow the next sequence:
- Close the feeding of the oil.
- Cooldown the boiler to the ambient
temperature.
- Switch Off the electrical supply to the boiler
and the burner.
- Open the front door.
- Shake and remove the turbulators every
15-20 days of activity of the boiler to avoid
that the residues of combustion can stop
them so much to make difficult their
removal).
- Clean the turbulators and the smoke pipes
by brushing them with the brush supplied.
- Reposition the turbulators.
- Remove the cleaning door and all the soot
from the smoke chamber.
- Re-fit the cleaning doors.
fig. 12
Turbulator
fig. 13
Round brush
fig. 14
fig. 15
Brush handle
Brush handle extension
(if applicable)
5.5 - CHECK OF THE
BOILER OPERATION
For a safe operation of the boiler it is necessary
to check:
- The good operation of the working
thermostat.
- The good operation of the high limit
thermostat.
- The adjustment and the good operation
of the minimum thermostat.
- The good operation of the shunt system.
- The good operation of the outer
compensator (if fitted).
5.7 - BOILER HOUSE
For the combustion of oil or gas the burner
needs air.
Accordingly wide openings are foreseen for
the entry of the air in the boiler house.
These openings never have to be obstructed.
Maintain the boiler house clean and dust free.
- Verify the state of the refractory insulation
of the combustion chamber door.
- Verify the state of the door sealing rope.
- Close the door of the furnace.
- The good operation of all the other safety
and control devices imposed by local
requirements.
5.6 - CHECK OF THE
BURNER OPERATION
- See the burner instruction manual.
- Follow all the local requirement in terms
of burner maintenance .
The boiler is not a closet: avoid to store any
kind of materials.
Maintain the entry of the boiler free and easy
to reach in any moment.
Ascertain that the boiler house is endowed
with efficient emergency lamp.
15
46033 Casteldario - Mantova - ITALIA - tel. +39.0376.57001 (r.a.) - telefax +39.0376.660556
www.unical.eu inf[email protected]
Unical AG declines any liability for the inaccuriaces that may appear due to errors in trascription or
printing. It also reserves the right to introduce those modifications to its products that it considers
necesssary or useful, without compromising the essential characteristics of the said products.
AG S.P.A.
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